This study investigates the impact of sharing research findings on lexical coverage and vocabulary size with L2 English students. This practical knowledge can be applied toward reading books and other materials. Research has suggested that knowing approximately 98% of the words in a text can lead to adequate reading comprehension (Hu & Nation, 2000). Such information, paired with knowledge of a student's own vocabulary size (Nation & Beglar, 2007), can potentially aid students in setting L2 vocabulary and reading goals. Ninety-nine university students in Thailand participated in this study. It utilizes a pretest-posttest design, with the sharing of research findings on lexical coverage and vocabulary size with students as the treatment. Surveys measuring motivation and attitudes toward studying L2 vocabulary were conducted before and after the treatment. Results were analyzed using principal component analysis, revealing three clear components among 12 traits. A comparison of the mean scores between components in the pretest and posttest surveys revealed statistically significant differences for two of the components (p=0.038 and 0.002). The changes in the scores from both components indicate improvements in motivation and attitudes toward studying L2 vocabulary.